From Tolkien Gateway

Sundóma is the Quenya name of the central radical vowel in a sundo, an etymological root.

In the process of a language, the sundóma took part in the following phenomena:

prefixing to a sundo its sundóma, usually together with its lengthening either in the first or in the last position.
A infixion
adding an a before the sundóma I creating an ohlon (diphthong):
I/Y infixion
putting an i/y after the sundóma creating an ohlon (less frequently occured than the previous one):


The word sundóma means "root-vowel",[1] from sundo "root" and óma "voice".[2]


  1. J.R.R. Tolkien, "Words, Phrases and Passages in Various Tongues in The Lord of the Rings", in Parma Eldalamberon XVII (edited by Christopher Gilson), p. 105
  2. Helge Fauskanger, "Quettaparma Quenyallo", Ardalambion (accessed 4 December 2022)